Sorry Americans: You just don’t have what it takes to make financial decisions.

So says a survey released recently by the TIAA Institute and the Global Financial Literacy Excellence Center (GFLEC) at the George Washington University School of Business.

On average, U.S. adults answered only half of 28 questions correctly in a TIAA Institute-GFLEC Personal Finance Index, which measures financial knowledge and understanding. Questions touched upon areas such as earning, saving, investing, risk and return, managing debt, insuring and comprehending risk.

Borrowing was the area where financial literacy was highest. Comprehending risk — and understanding uncertain financial outcomes — was the lowest.

Plenty of Americans need to learn about borrowing; survey respondents answered just 60% of questions about debt correctly. But folks really need to get a handle on comprehending risk. Survey respondents answered only 35% of those questions correctly.

Risk is something you likely learn in the school of hard knocks. But it would be far better to learn about the concepts associated with risk — such as hazards, exposure, probabilities and consequences — in elementary or high school.

“Having higher risk knowledge is correlated with being less likely to be financially fragile,” says Annamaria Lusardi, a George Washington University School of Business professor, founder and academic director of the GFLEC and report co-author.

Here's how to increase your know-how, and comfort, with risk:

Know that you won't always know

There's not always an easy, obvious answer. So try to get comfortable with making decisions when the outcome isn't certain, says Paul Yakoboski, a senior economist with the TIAA Institute and report co-author.

One way to do that is "to factor likelihoods and consequences of possible outcomes" into the decision-making process, he says.

A retiree who must convert substantial saving into a cash stream for decades to come may not know future rates of return. So while there isn't a clear “right answer” on what to do, but some financial strategies will certainly be more appropriate than others, says Yakoboski.

A knowledge of numbers will help you to better understand risk and potential benefits.(Photo: Amber Sigman, The (Louisville, Ky.) Courier-Journal)

Get comfortable with numbers

Many people have "trouble understanding numbers,” which can make risk assessment difficult, says David Ropeik, author of How Risky Is It, Really?

It gets especially difficult "when numbers are couched in terms of percentages, as in when one compares the percentage return on various investment choices," he says.

Lusardi says financial education can help. People "have to invest time to educate themselves about managing money,” she says. “It has a handsome payoff.”

People also need to think positively about what they can learn, so their thoughts don't hold them back, says Ellen Peters, psychology professor and director of the Decision Sciences Collaborative at The Ohio State University, as well as the author of a forthcoming book, Innumeracy in the Wild.

“Our subjective feelings can hold us back if we're nervous or simply think we're no good at it," she says.

And those who need some extra help should reach out to others.

“If you’re not good with numbers you could ask a professional — or someone you know who is good with numbers in finances — about what the numbers mean,” Peters says. “For example, if you're told that the expected rate of return is 8% per year, is that good or bad?

For instance, in two randomized trials, they showed improved understanding of risk and risk reduction for people in both high and low socioeconomic groups.

“People often have the skills to deal with numbers,” Woloshin and Schwartz wrote in an email. “The numerical skills for calculating savings from a sale are no different than the skills needed to understand the common risk statistics in the news and ads.”

If you don't learn how to tolerate risk, you could lost money.(Photo: RomoloTavani, Getty Images/iStockphoto)

Learn some rules of thumb

Think about using heuristics, which are otherwise known as rules-of-thumb, when making financial decisions, says Gerd Gigerenzer, author of Risk Savvy: How to Make Good Decisions. Some to consider:

Accumulate 10 times your salary in your retirement accounts by age 67

Allocate 50% of take-home pay for living expenses, 15% for retirement and 5% for an emergency fund

Understand inherent biases

People tend to suffer from optimism bias — which is thinking that things will turn out better for us, as compared with others — when considering the long-term things in life, says Ropeik.

Many people see the future with rose-colored glasses, and reassure themselves that they are saving and doing well. “This is true in every phase of life: health, vacations, job, marriage, investments," he says.

However, when risk is imminent, we suffer from loss aversion, which means we accentuate the prospect of potential loss, he says. People then "make choices to avoid losses that fly in the face of statistical probabilities,” says Ropeik.

He says these subjective filters pertain even when we understand the numbers.

"So even when our risk and numbers literacy is high, we still filter our borrowing and other financial choices through these lenses,” says Ropeik.

So, how might you counteract that? Ropeik says to consciously think about what you value - for instance, more money now or more money later. He says to think about the emotional price you are willing to pay in order to tolerate more risk.

“Then go read up on your financial history so you will know what to expect when the next crisis comes along, and it will,” he says.

Robert Powell is the editor of TheStreet’s Retirement Daily and contributes regularly to USA TODAY. Got questions about money? Email Bob at rpowell@allthingsretirement.com. The views and opinions expressed in this column are the author’s and do not necessarily reflect those of USA TODAY.